1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #include <linux/module.h> 3 #include <linux/netfilter/nf_tables.h> 4 #include <net/netfilter/nf_tables.h> 5 #include <net/netfilter/nf_tables_core.h> 6 #include <net/netfilter/nf_socket.h> 7 #include <net/inet_sock.h> 8 #include <net/tcp.h> 9 10 struct nft_socket { 11 enum nft_socket_keys key:8; 12 u8 level; 13 u8 len; 14 union { 15 u8 dreg; 16 }; 17 }; 18 19 static void nft_socket_wildcard(const struct nft_pktinfo *pkt, 20 struct nft_regs *regs, struct sock *sk, 21 u32 *dest) 22 { 23 switch (nft_pf(pkt)) { 24 case NFPROTO_IPV4: 25 nft_reg_store8(dest, inet_sk(sk)->inet_rcv_saddr == 0); 26 break; 27 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 28 case NFPROTO_IPV6: 29 nft_reg_store8(dest, ipv6_addr_any(&sk->sk_v6_rcv_saddr)); 30 break; 31 #endif 32 default: 33 regs->verdict.code = NFT_BREAK; 34 return; 35 } 36 } 37 38 #ifdef CONFIG_SOCK_CGROUP_DATA 39 static noinline bool 40 nft_sock_get_eval_cgroupv2(u32 *dest, const struct nft_pktinfo *pkt, u32 level) 41 { 42 struct sock *sk = skb_to_full_sk(pkt->skb); 43 struct cgroup *cgrp; 44 45 if (!sk || !sk_fullsock(sk) || !net_eq(nft_net(pkt), sock_net(sk))) 46 return false; 47 48 cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data); 49 if (level > cgrp->level) 50 return false; 51 52 memcpy(dest, &cgrp->ancestor_ids[level], sizeof(u64)); 53 54 return true; 55 } 56 #endif 57 58 static void nft_socket_eval(const struct nft_expr *expr, 59 struct nft_regs *regs, 60 const struct nft_pktinfo *pkt) 61 { 62 const struct nft_socket *priv = nft_expr_priv(expr); 63 struct sk_buff *skb = pkt->skb; 64 struct sock *sk = skb->sk; 65 u32 *dest = ®s->data[priv->dreg]; 66 67 if (sk && !net_eq(nft_net(pkt), sock_net(sk))) 68 sk = NULL; 69 70 if (!sk) 71 switch(nft_pf(pkt)) { 72 case NFPROTO_IPV4: 73 sk = nf_sk_lookup_slow_v4(nft_net(pkt), skb, nft_in(pkt)); 74 break; 75 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 76 case NFPROTO_IPV6: 77 sk = nf_sk_lookup_slow_v6(nft_net(pkt), skb, nft_in(pkt)); 78 break; 79 #endif 80 default: 81 WARN_ON_ONCE(1); 82 regs->verdict.code = NFT_BREAK; 83 return; 84 } 85 86 if (!sk) { 87 regs->verdict.code = NFT_BREAK; 88 return; 89 } 90 91 switch(priv->key) { 92 case NFT_SOCKET_TRANSPARENT: 93 nft_reg_store8(dest, inet_sk_transparent(sk)); 94 break; 95 case NFT_SOCKET_MARK: 96 if (sk_fullsock(sk)) { 97 *dest = sk->sk_mark; 98 } else { 99 regs->verdict.code = NFT_BREAK; 100 return; 101 } 102 break; 103 case NFT_SOCKET_WILDCARD: 104 if (!sk_fullsock(sk)) { 105 regs->verdict.code = NFT_BREAK; 106 return; 107 } 108 nft_socket_wildcard(pkt, regs, sk, dest); 109 break; 110 #ifdef CONFIG_SOCK_CGROUP_DATA 111 case NFT_SOCKET_CGROUPV2: 112 if (!nft_sock_get_eval_cgroupv2(dest, pkt, priv->level)) { 113 regs->verdict.code = NFT_BREAK; 114 return; 115 } 116 break; 117 #endif 118 default: 119 WARN_ON(1); 120 regs->verdict.code = NFT_BREAK; 121 } 122 123 if (sk != skb->sk) 124 sock_gen_put(sk); 125 } 126 127 static const struct nla_policy nft_socket_policy[NFTA_SOCKET_MAX + 1] = { 128 [NFTA_SOCKET_KEY] = { .type = NLA_U32 }, 129 [NFTA_SOCKET_DREG] = { .type = NLA_U32 }, 130 [NFTA_SOCKET_LEVEL] = { .type = NLA_U32 }, 131 }; 132 133 static int nft_socket_init(const struct nft_ctx *ctx, 134 const struct nft_expr *expr, 135 const struct nlattr * const tb[]) 136 { 137 struct nft_socket *priv = nft_expr_priv(expr); 138 unsigned int len; 139 140 if (!tb[NFTA_SOCKET_DREG] || !tb[NFTA_SOCKET_KEY]) 141 return -EINVAL; 142 143 switch(ctx->family) { 144 case NFPROTO_IPV4: 145 #if IS_ENABLED(CONFIG_NF_TABLES_IPV6) 146 case NFPROTO_IPV6: 147 #endif 148 case NFPROTO_INET: 149 break; 150 default: 151 return -EOPNOTSUPP; 152 } 153 154 priv->key = ntohl(nla_get_u32(tb[NFTA_SOCKET_KEY])); 155 switch(priv->key) { 156 case NFT_SOCKET_TRANSPARENT: 157 case NFT_SOCKET_WILDCARD: 158 len = sizeof(u8); 159 break; 160 case NFT_SOCKET_MARK: 161 len = sizeof(u32); 162 break; 163 #ifdef CONFIG_CGROUPS 164 case NFT_SOCKET_CGROUPV2: { 165 unsigned int level; 166 167 if (!tb[NFTA_SOCKET_LEVEL]) 168 return -EINVAL; 169 170 level = ntohl(nla_get_u32(tb[NFTA_SOCKET_LEVEL])); 171 if (level > 255) 172 return -EOPNOTSUPP; 173 174 priv->level = level; 175 len = sizeof(u64); 176 break; 177 } 178 #endif 179 default: 180 return -EOPNOTSUPP; 181 } 182 183 priv->len = len; 184 return nft_parse_register_store(ctx, tb[NFTA_SOCKET_DREG], &priv->dreg, 185 NULL, NFT_DATA_VALUE, len); 186 } 187 188 static int nft_socket_dump(struct sk_buff *skb, 189 const struct nft_expr *expr) 190 { 191 const struct nft_socket *priv = nft_expr_priv(expr); 192 193 if (nla_put_u32(skb, NFTA_SOCKET_KEY, htonl(priv->key))) 194 return -1; 195 if (nft_dump_register(skb, NFTA_SOCKET_DREG, priv->dreg)) 196 return -1; 197 if (priv->key == NFT_SOCKET_CGROUPV2 && 198 nla_put_u32(skb, NFTA_SOCKET_LEVEL, htonl(priv->level))) 199 return -1; 200 return 0; 201 } 202 203 static bool nft_socket_reduce(struct nft_regs_track *track, 204 const struct nft_expr *expr) 205 { 206 const struct nft_socket *priv = nft_expr_priv(expr); 207 const struct nft_socket *socket; 208 209 if (!nft_reg_track_cmp(track, expr, priv->dreg)) { 210 nft_reg_track_update(track, expr, priv->dreg, priv->len); 211 return false; 212 } 213 214 socket = nft_expr_priv(track->regs[priv->dreg].selector); 215 if (priv->key != socket->key || 216 priv->dreg != socket->dreg || 217 priv->level != socket->level) { 218 nft_reg_track_update(track, expr, priv->dreg, priv->len); 219 return false; 220 } 221 222 if (!track->regs[priv->dreg].bitwise) 223 return true; 224 225 return nft_expr_reduce_bitwise(track, expr); 226 } 227 228 static struct nft_expr_type nft_socket_type; 229 static const struct nft_expr_ops nft_socket_ops = { 230 .type = &nft_socket_type, 231 .size = NFT_EXPR_SIZE(sizeof(struct nft_socket)), 232 .eval = nft_socket_eval, 233 .init = nft_socket_init, 234 .dump = nft_socket_dump, 235 .reduce = nft_socket_reduce, 236 }; 237 238 static struct nft_expr_type nft_socket_type __read_mostly = { 239 .name = "socket", 240 .ops = &nft_socket_ops, 241 .policy = nft_socket_policy, 242 .maxattr = NFTA_SOCKET_MAX, 243 .owner = THIS_MODULE, 244 }; 245 246 static int __init nft_socket_module_init(void) 247 { 248 return nft_register_expr(&nft_socket_type); 249 } 250 251 static void __exit nft_socket_module_exit(void) 252 { 253 nft_unregister_expr(&nft_socket_type); 254 } 255 256 module_init(nft_socket_module_init); 257 module_exit(nft_socket_module_exit); 258 259 MODULE_LICENSE("GPL"); 260 MODULE_AUTHOR("Máté Eckl"); 261 MODULE_DESCRIPTION("nf_tables socket match module"); 262 MODULE_ALIAS_NFT_EXPR("socket"); 263